The long-term objective of this proposal is to improve ophthalmic care for patients with a pediatric ocular tumor, retinoblastoma (RB). We propose to provide rapid diagnosis and improved prognosis for patients with heritable ocular RB through improved genetic testing, and to innovate more effective and less toxic therapies for this ophthalmic disease.In pursuit of these objectives, two specific aims are proposed. These are: I. To develop and validate a protein truncation test (PTT) for detection of germline retinoblastoma gene (RB1) mutations and to determine whether mutation analysis can be used to predict ocular disease expression.This aim will be accomplished in 3 stages. We propose to: A. Develop PTT. B. Perform focused DNA sequencing to characterize RB1 mutations detected by PTT. C. Determine whether mutation analysis can be used to predict ocular disease expression .II. To determine the potential clinical utility of selected new pharmacologic agents in RB. These are: A. Cyclosporin A, and two potential alternatives, PSC-833 and FK506. B. Retinoids, including all-trans retinoic acid, ALRT1550, AM80, fenretinide, Targretin, 9-cis retinoic acid, and 13-cis retinoic acid.C. The alkylating agent, temozolomide. D. The blood-brain barrier permeabilizer, RMP-7 (Cereport).E. The tumor-specific viral agents, ONYX-015 and ONYX-RB1.These agents are chosen for their relatively low toxicity and potential efficacy in the management of this ocular tumor. These agents also have potential utility in the management of other ophthalmic disorders.